呵呵，N久没做网页了，这是在以前的文件里找的。
看了下魔兽的网站，可能是用了浮动的<div>等，你自己看看魔兽的javascript吧
地址：http://games.enet.com.cn/zhuanti/wow/js/tooltip.js
全文如下：
/***********************************************
* Cool DHTML tooltip script- Dynamic Drive DHTML code library (www.dynamicdrive.com)
* This notice MUST stay intact for legal use
* Visit Dynamic Drive at http://www.dynamicdrive.com/ for full source code
***********************************************/
var offsetxpoint=16 //Customize x offset of tooltip
var offsetypoint=-16 //Customize y offset of tooltip
var ie=document.all
var ns6=document.getElementById && !document.all
var enabletip=false
if (ie||ns6)
var contentobj=document.all?do
cument.all["contents"] :do
cument.getElementById?do
cument.getElementById("contents"
: ""
var tipTextObj=document.all?do
cument.all["tooltipText"] :do
cument.getElementById?do
cument.getElementById("tooltipText"
: ""
var dynamicTipObj=document.all?do
cument.all["dynamicTooltip"] :do
cument.getElementById?do
cument.getElementById("dynamicTooltip"
: ""
function ietruebody(){
return (document.compatMode &&do
cument.compatMode!="BackCompat"
?do
cument.documentElement :do
cument.body
}
function ddrivetip(thetext, thecolor, thewidth)
{
if (ns6||ie)
{
if (thetext.indexOf("~"
>= 0) tipTextObj.innerHTML = dynamicTipObj.innerHTML;
else
{
tipTextObj.innerHTML = thetext;
tipTextObj.style.color=thecolor;
}
if (typeof thewidth=="undefined"
{
contentobj.style.width=tipTextObj.clientWidth+"px";
contentobj.style.height=tipTextObj.clientHeight+"px";
}
else
{
contentobj.style.width=thewidth+"px";
}
enabletip=true;
return false
}
}
function positiontip(callingEvent)
{
if (enabletip)
{
if (!callingEvent) callingEvent = window.event;
var currentX = callingEvent.clientX + 14;
var currentY = callingEvent.clientY + 14 +do
cument.body.scrollTop;
contentobj.style.left = currentX+"px";
contentobj.style.top = currentY+"px";
contentobj.style.visibility = "visible";
tipTextObj.style.visibility = "visible";
//document.getElementById("mousePositionIndicator"
.innerHTML = currentX + "x, "
+ currentY + "y";
}
}
function posit_iontip(e)
{
if (enabletip)
{
var curX=(ns6)?e.pageX : event.x+ietruebody().scrollLeft;
var curY=(ns6)?e.pageY : event.y+ietruebody().scrollTop;
//Find out how close the mouse is to the corner of the window
var rightedge=ie&&!window.opera? ietruebody().clientWidth-event.clientX-offsetxpoint : window.innerWidth-e.clientX-offsetxpoint-20
var bottomedge=ie&&!window.opera? ietruebody().clientHeight-event.clientY-offsetypoint : window.innerHeight-e.clientY-offsetypoint-20
var leftedge=(offsetxpoint<0)? offsetxpoint*(-1) : -1000
//if the horizontal distance isn't enough to accomodate the width of the context menu
if (rightedge<contentobj.offsetWidth)
{
//move the horizontal position of the menu to the left by it's width
contentobj.style.left=ie? ietruebody().scrollLeft+event.clientX-contentobj.offsetWidth+"px"
: window.pageXOffset+e.clientX-contentobj.offsetWidth+"px"
}
else
if (curX<leftedge)
{
contentobj.style.left="5px"
}
else
{
//position the horizontal position of the menu where the mouse is positioned
contentobj.style.left=curX+offsetxpoint+"px"
}
//same concept with the vertical position
if (bottomedge<contentobj.offsetHeight)
{
contentobj.style.top=ie? ietruebody().scrollTop+event.clientY-contentobj.offsetHeight-offsetypoint+"px"
: window.pageYOffset+e.clientY-contentobj.offsetHeight-offsetypoint+"px"
contentobj.style.visibility="visible"
tipTextObj.style.visibility="visible"
}
else
{
contentobj.style.top=curY+offsetypoint+"px"
contentobj.style.visibility="visible"
tipTextObj.style.visibility="visible"
}
}
//for debugging purposes
//if (!e) e = window.event;
//document.getElementById("mousePositionIndicator"
.innerHTML = callingEvent.clientX + "x, "
+ callingEvent.clientY + "y";
}
function hideddrivetip(){
if (ns6||ie){
enabletip=false
contentobj.style.visibility="hidden"
contentobj.style.left="-1000px"
contentobj.style.backgroundColor=''
contentobj.style.width=''
}
}
document.onmousemove=positiontip
